Beginning with PLplot 5.0, a new and powerful paradigm for interaction with PLplot is introduced. This new paradigm consists of an integration of PLplot with a powerful scripting language (Tcl), and extensions to that language to support X Windows interface development (Tk) and object oriented programming ([incr Tcl]). Taken together, these four software systems (Tcl/Tk/itcl/PLplot) comprise a powerful environment for the rapid prototyping and development of sophisticated, flexible, X Windows applications with access to the PLplot API. Yet that is only the beginning—Tcl was born to be extended. The true power of this paradigm is achieved when you add your own, powerful, application specific extensions to the above quartet, thus creating an environment for the development of wholly new applications with only a few keystrokes of shell programming ...